NAVTEX On Ships
Every navigating officer must ensure the vessel’s and its crew’s safety. Even the most cautious and cautious navigator might have an accident. The navigator requires up-to-date information that will affect the ship’s passage from the beginning of the voyage planning process. The most vital information for ships is safety-related information, such as Maritime Safety Information.
Weather predictions, navigational and meteorological alerts, warnings regarding threats to operation, warning signs of lost vessels, and other critical communications relevant to the vessel’s and crew’s safety are all included in Maritime Safety Data.
NAVTEX, which stands for navigational telex (navigational text messages), is a mechanism used onboard ships to automatically transmit short-range Maritime Safety Information in coastal waters.It is suitable for all types and sizes of ships. Navtex’s coverage radius can reach up to 400 nautical miles from the broadcast station. Vessels equipped with a NAVTEX receiver receive navigational and meteorological warnings, predictions, and essential Marine Safety Information. It is an integral part of the Global Maritime Distress Safety System (GMDSS) (GMDSS). Navtex employs the radio telex or Narrow Band Direct Printing (NBDP) feature to automatically disseminate information.
WHAT IS NAVTEX, AND HOW DOES IT WORK?
The Navtex operates in the medium frequency band at 518 kHz. Some countries use the 490 kHz frequency for national language transmissions, sometimes known as national navtex.
Transmissions are made on 4209.5 kHz, where medium frequency reception is poor. 518 kHz is the default setting in a Navtex. To disseminate this information, the entire planet is divided into 21 zones known as NAVAREAS (including five areas recently introduced for the Arctic region).
Each Navarea features several navtex stations, which aid in transmitting messages.
All navtex receivers can be programmed so that only messages from specific Navtex Stations are shown or printed by the navigating officer. The SELECTING STATION menu on a Navtex Receiver’s Menu option allows the officer to choose which stations they want to receive automatically or manually.
The navtex gets Marine Safety Information for the ship’s area continually and without human intervention when it is set to automatic selection.
Suppose the location data from any navigating device, such as GPS, is supplied into the Navtex. In that case, the Navtex will automatically determine which NAVAREA the ship is now traveling to and choose the relevant Navtex Stations.
The navigating officer can choose which stations they want to receive in manual mode.
TYPES OF MESSAGES
The Navtex receives the following kind of messages:
- A= Navigational Warning
- B= Meteorological Warning
- C= Ice report
- D= Search and Rescue Information/ piracy and armed robbery
- E= Meteorological forecast
- F= Pilot messages
- G= AIS messages(formerly Decca messages)
- H= Loran C messages
- I= Omega messages
- J= Satnav messages (GPS or GLONASS)
- K= Other electronic navigational aid system messages
- L= navigational warnings (additional)
- M to U= Reserve
- V= Notice to fisherman
- W to Y= Reserve
- Z= No messages on hand
Navtex receivers can be programmed to disregard some types of signals. However, navigating officers cannot reject messages A, B, D, or L due to their importance. Audible alarms can be created when message types A, B, D, or L are received. This alarm should only be able to be reset manually.
It’s also worth noting that while programming the types of messages to receive, only those that are required and necessary should be configured for the reception.
Otherwise, a lot of paper will be wasted, and if the broadcasts are received in soft copy, one will have to scroll through many messages.
THE MESSAGE’S FORMATION
In a Navtex Receiver, the message is formatted as follows:
b1 b2 b3 b4 ZCZC PRIMARY MESSAGE NNNN
ZCZC: This is the initialization code. It denotes the start of the message.
B1: The Station ID is represented by this character.
B2: The Subject Indicator is the name of this character. It’s used to denote the message’s type. (From A to Z)
The navtex receivers employ the characters B1 and B2 to reject communications from stations about issues that the officer isn’t interested in.
B3 and B4: B3 and B4 have a two-digit serial number for each communication.
NNNN: This denotes the message’s conclusion.
Receivers utilize the characters B3 and B4 to track what they’ve already received.
THE BENEFITS OF HAVING NAVTEX ONBOARD THE SHIPS INCLUDE:
Navtex is a type of additional insurance that provides peace of mind. It’s a simple way to keep track of navigational alerts, weather warnings, search and rescue information, and other data for ships traveling within 200 to 400 nautical miles of the coast. As a result, it gives up-to-date navigational and weather data in real-time.
The Navtex receiver is very user-friendly because it receives messages automatically. It is not necessary for an officer of the watch to monitor it regularly or be physically there at a set hour.
A watch officer can attend to any distress signal in the area. He’s also aware of the weather forecast and can make plans accordingly. As a result, a Navtex is an essential piece of bridge navigational equipment.
CHECKLIST FOR NAVTEX RECEIVERS
- At all times, every officer should ensure enough rolls of Navtex paper onboard.
- It’s crucial to double-check that the receiver has paper in it so that no important messages are missed.
- To avoid losing crucial information that could disrupt the vessel’s voyage, it’s best to keep the Navtex turned on.
- Ensure that the bridge’s operating manual is accessible.
- Next to the equipment should be a plastic duplicate of the NAVAREAs/METAREAS in which the vessel is expected to travel, displaying the Navtex stations, their coverage ranges, and their respective time schedules.
- Users can make and keep a convenient guide for programming, status, and auto testing processes with the equipment.
- Testing the equipment’s performance should be done regularly.
- It’s essential not to mix up the programming of B1 characters (station designators) and B2 characters (type of messages).
All SOLAS-approved vessels are required to carry Navtex. It’s a small piece of equipment, but it packs a punch. It delivers safety information that may be customized to meet a person’s specific requirements.
To know more, please check our Navtex Product page